The present invention relates to devices and methods for enhancing enjoyment of electronically reproduced music.
Advances in audio technology have resulted in systems capable of quite accurately reproducing music over the entire range of audibility (approximately 12-20,000 Hertz). A multitude of individual audio components are available that may be combined to reproduce music having very little distortion of the input audio signal. These audio systems are also capable of producing sounds at a very high amplitude.
The enjoyment of listening to music is not limited to auditory perception, but in addition, it includes the receiving of the acoustic vibrations of music through the body. The human body "feels" vibrations primarily in the extremely low frequency (hereinafter ELF or bass), range of less than 250 Hertz. Unfortunately, in order to generate a bass level of sound that is enjoyable in this manner, it is often necessary to turn the volume level of the system up to a very high level. The result may be a volume that may injure the ears of people in close proximity or disturb people in adjacent areas. Quite often bass levels that are sufficiently loud to be enjoyed by intended listeners are transmitted through walls and ceilings, disturbing the unintended. Alternatively, the audio system controls may be adjusted to provided more bass and/or less treble, but this results in a distorted output.
Paii U.S. Pat. No. 2,821,191 discloses a pulsating device, in particular, a treatment table wherein pulsations produced are controlled somewhat in proportion to the volume of sound waves emanating from a loudspeaker. In Paii, the variations in vibration from a speaker are used to control the current delivered to a pulsator motor. Connected to the output shaft of the pulsator motor are eccentrics. It is the movements of these eccentrics that create the vibrations perceived by the user of the device.
Nohmura U.S. Pat. No. 3,880,151 discloses a health promoting device comprising a chair or a bed with loudspeakers incorporated within to generate rhythmical vibrations. The sounds generated by the loudspeakers are propagated through an air space between the speakers and the surface of the chair or bed before they reach the person resting upon the chair or the bed.
Martinmaas U.S. Pat. No. 4,023,566 discloses the use of loudspeakers in either chairs or beds, where the speakers are mounted in chambers filled with air facing the body support structure. The speakers produce vibrations within the chamber which are propagated through the air within the chamber to reach and be heard before they are felt by the occupant.
Smith U.S. Pat. No. 4,507,816 discloses a sound wave system for use with a water bed where sounds from loudspeakers located in individual airtight speaker enclosures are directed upwardly through the air within the speaker enclosure into the water-filled mattress to create water waves and vibrations that are synchronized with the sound.
All of the above-described devices have the goal of producing vibrations that are representative of the full range of frequencies contained in the source music. With the exception of the Paii device, all of the prior apparatus relies upon the transmission of sound waves through air prior to being absorbed into the body.
Because sound waves spread widely in air, especially at lower frequencies, it is difficult to create pleasant bass vibrations which can be felt within a human body, using air to transmit the sound, without disturbing people who do not want to hear the sound.
What is needed, therefore, is an improved apparatus that will allow the user to listen to a properly balanced audio output at a reasonable volume while enjoying feeling the bass vibrations.